Manufacture of seamless pipes



fig 6 fig. 2

3 Sheets-Sheet 1 M. ROECKNER Filed August 5 1925 MANUFACTURE OF SEAMLESSPIPES M. ROECKNER MANUFACTURE OF SEAMLESS PIPES Dec. 14 1926.

1925 3' Sheets-Sheet ,2

Filed August 5,

.lflllil lt ligesses: 4

I Dec. 14-, 1926.

1,610,593 M. ROECKNER MANUFACTURE OF SEAMLESS PIPES Filed August 5, 19255 Sheets-Shoat 3 Mfr eases Patented Dec. 14, 1926.

UNITED STATES v f 1,610,593 PATENT OFFICE.

MARTIN ROECKNI ER, OF EULHEIM-BUHR, GERMANY.

MANUFACTURE or SEAMLESS rrrns.

Application filed August 5,1925, Serial No. 48,368, and in Germany June24, 1922.

It is already known to make seamless pipes of a hollow blockby rollingit both inside and outside starting at a point, rolling it out andsmoothing toward the end of pipe. It --l has further beenproposed, forinstance, to use a rolling mill with inner and outer pairs of rolls ofwhich the axes are located parallel to the pipe axis, the rolls beingarranged on a circular arc,'of equal width and of crowned or curvedformation. Owing to this arrangement, the stretchinggof the materialtakes place mainly in the direction of the pipe circumference, so thatthe pipe receives by its working an increased diameter. Further more. asimilar-rolling mill is, known, in

which the rolls are at an opposite angle arranged obliquely to thelongitudinal direction of the machinein order to produce also an advanceof. the pipe in the longitudinal direction, the pipe being clamped fastso that it cannot turn on its own axis while the rolls are arranged in acasing revolving around the pipe, It has also been proposed in a similarrolling mill of which the obliquely arranged rolls produce helicalgrooves on the pipe,,to insert, between the I single stock-casingscarrying the rolls, smoothing rollers for smoothing the bulbs formedbetween the rolled grooves.

From this known art, the present invention is distinguished bythe factthat. a seamless pipe is rolled from a rotating hollow block byseparating part of the material of the block from the remaining part bythe utilization of rollerpairs of gradually increasing width and ofadiustable working depth uniformlv distributed over the circumference ofthe block along a helical line behind each other, each roller pairacting both from inside and outside upon said block, thereby producing acircumferential nick in the block beginning adjacent one end of theblock and graduallywidening said nick toward said end. r

In the accompanying drawings,

Figs. 1 to 4 show diagrammatically the difierent successive steps oftreatment of the wall of, the hollow block (shown in longitudinalsection) by the pairs of rolls;

Figs. 5 to 8 show similar views to the former, of a different mode ofapplication of the pair of rolls to the wall of the hollow block.

Figs. 9 and 10 show respectively in a perpendicular central section andin asectional plan view, a preferred constructional form of the improvedrolling mill in which the hollow block is treated while in itsperpendicular position and moved in perpendicular direction, While Fig.11 shows a longitudinalcentral section of another rolling millembodyingthe present inventionv in which the hollow block is treated while in itshorizontal position and moved in horizontal direction.

Referring to Figs. 1 to 4: First, a pair of narrow rolls 2, 3 producesduring its revolution a circumferential nick in the wall-1 of the hollowblock at a short distance from one end of the latter, which nick is thengradually widened toward said end by other pairs of rolls 4, 56, 7-8, 9of inoreasi g width until it is flush with said end. in this example,the pairs of rolls produce the nick in the. wall of the hollow blockfrom inside and outside at the same time.

:Referring to Figs. 5 to 8, only one roll of the'pairs of rolls, forinstance the inner one, 24 -8*,' acts to produce the circumferentialnick, while theother one, 5 7 serves as a counterbearing only, for whichpurpose it can be of equal,

rather broad width, in all pairs of rolls,

Referring to Figs. 9 and 10: The rolling mill illustrated, has fourpairs of rolls 2", 3 -4 5"6", 7 and 8, the outer one of this latter pairbeing not shown on the drawing. The outer rolls thereof are mounted insupports 10, which. can be adjusted with reference to the hollow block1, for the purpose of regulating the depth of the circumferential nickto be produced therein and thus the desired wall thickness of theseamless pipe, in a frame 11 by means of a screwgear 12, 13; the drivingof the rolls being effected from driving-spindles 14 by means ofbevel-gea'rings 15, 16. The inner rolls are mounted in supports 17,which are radially slidable in a correspondingly designed head 18 of astationary upright cylinder 29 around" which the hollow block 1 islocated, the inner ends of said supports being in contact witha-wedge-pieoe 19 arranged in said cylinder and adapted to be adjusted,for regulating the depth of the nick and thus the desired wall thicknessof the seamless pipe, by means of ascrew-gear 20, 21. The pairs of rollsare uniformly distributed over the circumfer- I ence of the block andarranged along a helical line behind each other, so that first the rolls2", 3 act upon the hollow block 1, then the rolls 4*, 5 and 6, 7 andfinally the pair of rolls 8", of which one only is shown. As

aforementioned, thereby, part of the material is separated from theremaining part diametral direction, whereby the rolls and their supportsaid in balancing those forces issuing from the work-piece and having aone-s1 e rolls. The hollow block is during its treatment rotated, sothat the part worked by the first pair of rolls 2", 3 is then offeredto'th'e action of the second pair, and so on. The rotation of the hollowblock 1 is effected partly, or exclusively, by the driving gear of thepairs of rolls. The latter can also be used at the same time foradvancing the hollow blockl provided that their axes, corresponding tothe helical line, are located in oblique direction to the axis of thehollow block. Separate supporting-rollers (not illustrated) may beprovided for maintaining the hollow block in its perpendicular position.

Referring to Fig. 11: The hollow block 1 is here worked in itshorizontal position.

' The head 22 carrying the four inner rolls,

of which 2 and 6 only are shown, is arranged on a; horizontal arm 23,which is turnably mounted on t'ru'nnions 24 in a frame 25, the free endof said arm carrying a counterweight 26 The dis lacement of thewedge-piece 19, which is xed to a screwrod 27, takes place byanadjusting nut 28 on the latter. Separate supporting-rollers (notillustrated) must be provided for carrying (1 direction toward thecentres of the "the hollow block 1 in its horizontal position. The otherreference letters indicate similar parts to those in Fi 9 and 10,namely: 17 the radially adjusta le supports for the inner rolls adaptedto be acted upon by the wedge-piece 19; 10' the adjustable supports forthe outer rolls in the frames 11 and 12, 13 and 14, 15, 16 thedriving-gears for the outer rolls.

The arrangement shown in Figs. 9 and 10, is, however, more advantageousby reason of the cylinder 29 being not exposed to bending strains by theweight of the head 18 and the inner rolls, so that it can be thin-walledand thus suflicient room is gained therein for mounting the wedge-piece19.

Instead of four pairs of rolls illustrated, of course, any otherappropriate number can be used according to actual circumstances.

What I claim, is:

The herein described method of rolling seamless pipes from a rotatinghollow block, which consists in separating part of the material of theblock from the remaining part by the utilization of roller pairs ofgradually increasing width and of adjustable working depth uniformlydistributed over the circumference of the block along a helical linebehind each other, each roller pair acting both from inside and outsideupon said back, thereby producing a circumferential nick in the blockalong a helical line beginning adjacent one end of the block andwidening said nick toward said end.

In testimony whereof I have hereunto setmy hand.

- MARTIN ROECKNER.

'45 which can be adjusted by the screw-gears

